Papaloapan River in the context of Alvarado Lagoon

Tres Zapotes is a Mesoamerican archaeological site located in the south-central Gulf Lowlands of Mexico in the Papaloapan River plain. Tres Zapotes is sometimes referred to as the third major Olmec capital (after San Lorenzo Tenochtitlán and La Venta), but the Olmec phase is only a portion of the site's history, which continued through the Epi-Olmec and Classic Veracruz cultural periods.

The 2000-year existence of Tres Zapotes as a cultural center is unusual, if not unique, in Mesoamerica.

The Epi-Olmec culture was a cultural area in the central region of the present-day Mexican state of Veracruz. Concentrated in the Papaloapan River basin, a culture that existed during the Late Formative period, from roughly 300 BCE to roughly 250 CE. Epi-Olmec was a successor culture to the Olmec, hence the prefix "epi-" or "post-". Although Epi-Olmec did not attain the far-reaching achievements of that earlier culture, it did realize, with its sophisticated calendrics and writing system, a level of cultural complexity unknown to the Olmecs.

Tres Zapotes and eventually Cerro de las Mesas were the largest Epi-Olmec centers though neither would reach the size and importance of the great Olmec cities before them nor El Tajín after them. Other Epi-Olmec sites of note include El Mesón, Lerdo de Tejada, La Mojarra, Bezuapan, and Chuniapan de Abajo.

Classic Veracruz culture (or Gulf Coast Classic culture) refers to a cultural area in the north and central areas of the present-day Mexican state of Veracruz, a culture that existed from roughly 100 to 1000 CE, or during the Classic era.

El Tajin was the major center of Classic Veracruz culture; other notable settlements include Higueras, Zapotal, Cerro de las Mesas, Nopiloa, and Remojadas, the latter two important ceramics centers. The culture spanned the Gulf Coast between the Pánuco River on the north and the Papaloapan River on the south.

The Atoyac River is a river in Oaxaca, Mexico. The Atoyac flows into the Rio Verde which empties into the Pacific near Laguna Chacahua, in Lagunas de Chacahua National Park, 90 km west of Puerto Escondido. The mountainous terrain of the region it occupies allows for no navigable rivers; instead, there are a large number of smaller ones, which often change name from area to area. The continental divide passes through the state, meaning that there is drainage towards both the Gulf of Mexico and the Pacific Ocean. Most of the drainage towards the Gulf is represented by the Papaloapan and Coatzacoalcos Rivers and their tributaries such as the Grande and Salado Rivers. Three rivers account for most of the water headed for the Pacific: the Mixteco River, Tehuantepec River, and the Atoyac, with their tributaries.

During 1984's Hurricane Odile, eighteen passengers and three crewman drowned in flooding on the Atoyac River.

The Mazatec are an Indigenous people of Mexico who inhabit the Sierra Mazateca in the state of Oaxaca and some communities in the adjacent states of Puebla and Veracruz.

Some researchers have theorized that the Mazatec, along with Popoloca speakers, once inhabited the lowlands of the Papaloapan basin, but were driven into the adjacent highlands by the expansion of Nahuas.

Totonacapan refers to the historical extension where the Totonac people of Mexico dominated, as well as to a region in the modern states of Veracruz and Puebla. The historical territory was much larger than the currently named region, extending from the Cazones River in the north to the Papaloapan River in the south and then west from the Gulf of Mexico into what is now the Sierra Norte de Puebla region and into parts of Hidalgo. When the Spanish arrived, the Totonac ethnicity dominated this large region, although they themselves were dominated by the Aztec Empire. For this reason, they allied with Hernán Cortés against Tenochtitlán. However, over the colonial period, the Totonac population and territory shrank, especially after 1750 when mestizos began infiltrating Totonacapan, taking political and economic power. This continued into the 19th and 20th centuries, prompting the division of most of historical Totonacpan between the states of Puebla and Veracruz. Today, the term refers only to a region in the north of Veracruz where Totonac culture is still important. This region is home to the El Tajín and Cempoala archeological sites as well as Papantla, which is noted for its performance of the Danza de los Voladores.

The Santo Domingo River, in the Mexican state of Oaxaca, is one of the main tributaries of the Papaloapan River. It is formed by the confluence of the Salado and Grande rivers, which drain the dry Tehuacán and Cuicatlán valleys west of the Sierra Madre de Oaxaca. The Santo Domingo river flows east through the Sierra Madre, dividing the Sierra Zongolica sub-range to the north from the Sierra Juárez to the south. It joins with the Valle Nacional River above San Juan Bautista Tuxtepec to form the Papaloapan.

Carrying sediment from the mountains, it was a major cause of flooding in the coastal plain of Veracruz by reducing the capacity of the Papaloapan to drain the plains.To alleviate these problems, the Cerro de Oro Dam was constructed on the river just above the junction with the Valle Nacional, completed in 1989. The reservoir behind the dam is connected by a channel to Lake Miguel Alemán, the reservoir formed by the Miguel Alemán Dam on the Tonto River.

The Valle Nacional River is a river of Oaxaca state in Mexico.The river originates in the Sierra Juárez.The ecology of the region, originally one of pine forests, is threatened by logging, agriculture and grazing.The Valle Nacional flows past San Juan Bautista Valle Nacional, and joins the Santo Domingo River to the southwest of San Juan Bautista Tuxtepec to form the Papaloapan River.

The Tonto River is a river of Oaxaca, Mexico that flows from the mountains of Zongolica. It is dammed by the Miguel Alemán Dam near the town of Temascal or Nuevo Soyaltepec, forming the Miguel Alemán Lake.Below the dam, the river flows southeast past San Juan Bautista Tuxtepec, where it joins the Santo Domingo River to form the Papaloapan River.